CBSE Class 12 · 2015 · Delhi · Coordination CompoundsShort Answer

i) Draw the geometrical isomers of the complex [Pt(NH

_{3}

)

_{2}

_{2}

].
ii) On the basis of crystal field theory, write the electronic configuration for a d⁴ ion if Δ

_{0}

< P.
iii) Write the hybridisation and magnetic behaviour of the complex [Ni(CO)

_{4}

]. (Atomic number of Ni = 28)

Answer: (i) cis (Cl's 90°) and trans (Cl's 180°) square-planar forms. (ii) t₂g³eg¹ (high-spin). (iii) sp³, diamagnetic.

Solution

(i) Square-planar [Pt(NH

_{3}

)

_{2}

_{2}

]: \textit{cis} — the two Cl

^{-}

on adjacent corners; \textit{trans} — the two Cl

^{-}

on opposite corners.
(ii) Δ

_{0}

< P (weak field): the fourth electron avoids pairing and enters e

_{g}

—

t_{2g}^{3} e_{g}^{1}

(iii) Ni(CO)

_{4}

: Ni(0) rearranges to 3d

^{10}

under strong-field CO; hybridisation \textbf{sp

^{3}

} (tetrahedral), all electrons paired — \textbf{diamagnetic}.

CBSE Class 12 Board · 2015 · Delhi · Subjective